diff mbox series

[v3,04/12] watchdog: s3c2410: Let kernel kick watchdog

Message ID 20211107202943.8859-5-semen.protsenko@linaro.org (mailing list archive)
State Accepted
Headers show
Series watchdog: s3c2410: Add Exynos850 support | expand

Commit Message

Sam Protsenko Nov. 7, 2021, 8:29 p.m. UTC 
When "tmr_atboot" module param is set, the watchdog is started in
driver's probe. In that case, also set WDOG_HW_RUNNING bit to let
watchdog core driver know it's running. This way watchdog core can kick
the watchdog for us (if CONFIG_WATCHDOG_HANDLE_BOOT_ENABLED option is
enabled), until user space takes control.

WDOG_HW_RUNNING bit must be set before registering the watchdog. So the
"tmr_atboot" handling code is moved before watchdog registration, to
avoid performing the same check twice. This is also logical because
WDOG_HW_RUNNING bit makes WDT core expect actually running watchdog.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
---
Changes in v3:
  - Added R-b tag by Krzysztof Kozlowski

Changes in v2:
  - Added explanation on moving the code block to commit message
  - [PATCH 03/12] handles the case when tmr_atboot is present but valid
    timeout wasn't found

 drivers/watchdog/s3c2410_wdt.c | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

Comments

Guenter Roeck Nov. 17, 2021, 1:34 p.m. UTC | #1 
On Sun, Nov 07, 2021 at 10:29:35PM +0200, Sam Protsenko wrote:
> When "tmr_atboot" module param is set, the watchdog is started in
> driver's probe. In that case, also set WDOG_HW_RUNNING bit to let
> watchdog core driver know it's running. This way watchdog core can kick
> the watchdog for us (if CONFIG_WATCHDOG_HANDLE_BOOT_ENABLED option is
> enabled), until user space takes control.
> 
> WDOG_HW_RUNNING bit must be set before registering the watchdog. So the
> "tmr_atboot" handling code is moved before watchdog registration, to
> avoid performing the same check twice. This is also logical because
> WDOG_HW_RUNNING bit makes WDT core expect actually running watchdog.
> 
> Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
> Changes in v3:
>   - Added R-b tag by Krzysztof Kozlowski
> 
> Changes in v2:
>   - Added explanation on moving the code block to commit message
>   - [PATCH 03/12] handles the case when tmr_atboot is present but valid
>     timeout wasn't found
> 
>  drivers/watchdog/s3c2410_wdt.c | 26 +++++++++++++++-----------
>  1 file changed, 15 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
> index 00421cf22556..0845c05034a1 100644
> --- a/drivers/watchdog/s3c2410_wdt.c
> +++ b/drivers/watchdog/s3c2410_wdt.c
> @@ -604,6 +604,21 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
>  	wdt->wdt_device.bootstatus = s3c2410wdt_get_bootstatus(wdt);
>  	wdt->wdt_device.parent = dev;
>  
> +	/*
> +	 * If "tmr_atboot" param is non-zero, start the watchdog right now. Also
> +	 * set WDOG_HW_RUNNING bit, so that watchdog core can kick the watchdog.
> +	 *
> +	 * If we're not enabling the watchdog, then ensure it is disabled if it
> +	 * has been left running from the bootloader or other source.
> +	 */
> +	if (tmr_atboot) {
> +		dev_info(dev, "starting watchdog timer\n");
> +		s3c2410wdt_start(&wdt->wdt_device);
> +		set_bit(WDOG_HW_RUNNING, &wdt->wdt_device.status);
> +	} else {
> +		s3c2410wdt_stop(&wdt->wdt_device);
> +	}
> +
>  	ret = watchdog_register_device(&wdt->wdt_device);
>  	if (ret)
>  		goto err_cpufreq;
> @@ -612,17 +627,6 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
>  	if (ret < 0)
>  		goto err_unregister;
>  
> -	if (tmr_atboot) {
> -		dev_info(dev, "starting watchdog timer\n");
> -		s3c2410wdt_start(&wdt->wdt_device);
> -	} else {
> -		/* if we're not enabling the watchdog, then ensure it is
> -		 * disabled if it has been left running from the bootloader
> -		 * or other source */
> -
> -		s3c2410wdt_stop(&wdt->wdt_device);
> -	}
> -
>  	platform_set_drvdata(pdev, wdt);
>  
>  	/* print out a statement of readiness */
> -- 
> 2.30.2
>
diff mbox series

Patch

diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
index 00421cf22556..0845c05034a1 100644
--- a/drivers/watchdog/s3c2410_wdt.c
+++ b/drivers/watchdog/s3c2410_wdt.c
@@ -604,6 +604,21 @@  static int s3c2410wdt_probe(struct platform_device *pdev)
 	wdt->wdt_device.bootstatus = s3c2410wdt_get_bootstatus(wdt);
 	wdt->wdt_device.parent = dev;
 
+	/*
+	 * If "tmr_atboot" param is non-zero, start the watchdog right now. Also
+	 * set WDOG_HW_RUNNING bit, so that watchdog core can kick the watchdog.
+	 *
+	 * If we're not enabling the watchdog, then ensure it is disabled if it
+	 * has been left running from the bootloader or other source.
+	 */
+	if (tmr_atboot) {
+		dev_info(dev, "starting watchdog timer\n");
+		s3c2410wdt_start(&wdt->wdt_device);
+		set_bit(WDOG_HW_RUNNING, &wdt->wdt_device.status);
+	} else {
+		s3c2410wdt_stop(&wdt->wdt_device);
+	}
+
 	ret = watchdog_register_device(&wdt->wdt_device);
 	if (ret)
 		goto err_cpufreq;
@@ -612,17 +627,6 @@  static int s3c2410wdt_probe(struct platform_device *pdev)
 	if (ret < 0)
 		goto err_unregister;
 
-	if (tmr_atboot) {
-		dev_info(dev, "starting watchdog timer\n");
-		s3c2410wdt_start(&wdt->wdt_device);
-	} else {
-		/* if we're not enabling the watchdog, then ensure it is
-		 * disabled if it has been left running from the bootloader
-		 * or other source */
-
-		s3c2410wdt_stop(&wdt->wdt_device);
-	}
-
 	platform_set_drvdata(pdev, wdt);
 
 	/* print out a statement of readiness */